You have mischaracterized what I am refering to as anti-Scriptural.
Against Scripture. Contrary to Scripture.
1)Saying Mary was 14 years old when she conceived is NOT anti-Scriptural. It doesn't contradict Scripture. It may be true it may be false.
2) Saying Jesus was 33 years old when he died IS Anti-Scriptural. I'll let you figure out why (and it has nothing to do with his eternal pre-existence).
Boy are you out in left field... Did Jesus die or not? Shall we change your name from "Nestorian" to "Docetist"?
And the same situation applies to the statement that Mary never had other childrem. IT IS NOT in scripture.
Is it so difficult to see that the Holy Family may have had close relatives (perhaps even raised in their home) who would have been called the Lord's brothers? When you read Luke Chapter 2 do you find any indication of siblings?